text: The United States Court of Appeals for the Sixth Circuit noted that it would be impossible for the Sherman Act to prohibit every restraint of trade for that would even encompass employment contracts, which, by their nature, restrain the employee from working elsewhere while they are being paid to work for the employer. Therefore, reasonable restraints were permitted, but this would only apply if the restraint was ancillary to the main purpose of the agreement. No conventional restraint of trade can be enforced unless it is both ancillary to the main purpose of the lawful contract and necessary to protect the enjoyment of legitimate fruits of the contract or protect from the danger of unjust use of those fruits by the other party.
  If the primary purpose is to restrain trade, then the agreement is invalid, and in this case, the restraint was direct and therefore invalid.
  The opinion was written by Chief Judge William Howard Taft (who later became President of the United States and then Chief Justice of the United States Supreme Court). Taft's reasoning was subsequently adopted by the Supreme Court as the proper interpretation of the Sherman Act.